Roll on the Floor (ROF) breakers which are associated with so-called “draw out breakers” are known. An example of a prior art ROF breaker is shown in FIG. 1. The ROF breakers can be configured to roll into a cell for engaging with components into an operative position. ROF breakers are available in various sizes typically as small and large units with vacuum breakers, e.g., medium voltage circuit breakers, and components ranging in weight from about 250 pounds to about 1200 pounds. The ROF breakers can be used in a number of utility, commercial, industrial and residential environments including distribution stations, main stations, power plants, shops and offices, commercial buildings, industrial production facilities and the like, as is well known to those of skill in the art.
As shown in FIG. 1, the prior art ROF breaker 10 includes four, one on each corner, small diameter metal wheels 10w which can provide sufficient support for the unit but can make the ROF breaker 10 difficult to push forward on a support surface as well as making it difficult to spin, turn or rotate. These types of products are typically lifted onto elevated rails, then racked into the switchgear. Other known prior designs for ROF breakers include units with four swivel wheels such as wheels that can roll directly into the cell from the floor.
Despite the above, there remains a need for alternate ROF breaker designs that are easier to maneuver and that can withstand the unit weight loads.